Rigid flex board module and the manufacturing method thereof

ABSTRACT

A rigid flex board module includes a rigid flex circuit board and a high-density interconnected circuit board. The rigid flex circuit board includes a flexible circuit board, a first rigid circuit board and a first adhesive layer. The flexible circuit board includes a bending portion and a jointing portion connected to the bending part. The rigid flex circuit board is disposed on the jointing portion to expose the bending portion. The first rigid circuit board electrically connects with the flexible circuit board. The first adhesive layer connects the first rigid circuit board and the jointing portion. The high-density interconnected circuit board is disposed in the first rigid circuit board and is electrically connected to the first rigid circuit board.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims the prioritybenefit of a prior application Ser. No. 14/093,660, filed on Dec. 2,2013, now allowed, which claims the priority benefit of Taiwanapplication serial no. 102130435, filed on Aug. 26, 2013. The entiretyof each of the above-mentioned patent applications is herebyincorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The instant disclosure relates to a rigid flex board module and themanufacturing method of the same; in particular, to a rigid flex boardmodule including a high-density interconnected circuit board and themanufacturing method of the same.

2. Description of Related Art

Conventional rigid flex board module includes a flexible circuit board,a rigid circuit board and an adhesive layer. The flexible circuit boardtypically includes a bending portion and a jointing portion connected tothe bending portion. The rigid circuit board is disposed on the jointingportion and exposes the bending portion to provide flexible yet rigidproperties.

The trend of 3C product such as smart phones, liquid crystal displays,PC tablets and laptops has been toward multifunction, so that the highdensity circuitry in rigid flex board modules is indispensable.

SUMMARY OF THE INVENTION

The object of the instant disclosure is to provide a rigid flex boardmodule having partial high-density interconnected circuit design and amanufacturing method for the rigid flex board module.

In order to achieve the aforementioned objects, according to anembodiment of the instant disclosure, a rigid flex board module isprovided, which includes a rigid flex circuit board and a high-densityinterconnected circuit board. The rigid flex circuit board includes aflexible circuit board, a first rigid circuit board and a first adhesivelayer. The flexible circuit board includes a bending portion and ajointing portion connected to the bending portion. The first rigidcircuit board is disposed on the jointing portion exposing the bendingportion. The first rigid circuit board is electrically connected to theflexible circuit board. The first adhesive layer is connected to thefirst rigid circuit board and the jointing portion. The high-densityinterconnected circuit board is disposed in and electrically connectedto the first rigid circuit board.

The instant disclosure also provides a manufacturing method forproviding the rigid flex board module. The method includes providing arigid flex initial substrate including a flexible circuit board, a firstrigid substrate, and a first insulating layer. The flexible circuitboard includes a bending portion and a jointing portion connected to thebending portion. The first rigid substrate is arranged above theflexible circuit board and the first insulating layer connects the firstrigid substrate and the flexible circuit board. A second opening isformed on the rigid flex initial substrate and through the first rigidsubstrate and the first insulating layer. A high-density interconnectedcircuit layer is disposed in the second opening. A pair of insulatingadhesive layers is formed on two sides of the rigid flex initialsubstrate. A pair of multi-layer circuit layers is formed on theinsulating adhesive layers. A plurality of conductive posts is formed inthe insulating adhesive layers such that the multi-layer circuit layers,the high-density interconnected circuit layer, and the rigid flexinitial substrate are electrically connected to each other.Successively, portions of the first rigid substrate, portions of thefirst insulating layer, portions of the insulating adhesive layer, andportions of the multi-layer circuit layer above the bending portion areremoved.

In summary, the instant disclosure provides a rigid flex board moduleand the manufacturing method for the same. The rigid flex board moduleincludes a rigid flex circuit board and a high-density interconnectedcircuit board. The high-density interconnected circuit board is disposedin the rigid flex circuit board where high density circuit design ispreferred. Since the high-density interconnected circuit board and therigid flex circuit board in the manufacturing method of the instantdisclosure can be separately designed, circuitry can first be designedon the high-density interconnected circuit board to reduce poor overallyield due to poor installation of the high-density interconnectedcircuit board in the rigid flex circuit board, thus increase yield.

In order to further understand the instant disclosure, the followingembodiments and illustrations are provided. However, the detaileddescription and drawings are merely illustrative of the disclosure,rather than limiting the scope being defined by the appended claims andequivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-section view of a rigid flex board module inaccordance with a first embodiment of the instant disclosure;

FIG. 1B to 1G are cross-sectional views of a manufacturing method forthe rigid flex board module in accordance with the first embodiment ofthe instant disclosure;

FIG. 2A to 2B are cross-sectional views of the manufacturing method forthe rigid flex board module in accordance with a second embodiment ofthe instant disclosure; and

FIG. 3 is a cross-sectional view of the rigid flex board module inaccordance with a second embodiment of the instant disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The aforementioned illustrations and detailed descriptions areexemplarities for the purpose of further explaining the scope of theinstant disclosure. Other objectives and advantages related to theinstant disclosure will be illustrated in the subsequent descriptionsand appended drawings.

Please refer to FIG. 1A. A rigid flex module 1 includes a rigid flexcircuit board 10″, a high-density interconnected circuit board 800, twopairs of multi-layer circuit layers 410′, 420′, a plurality ofconductive posts 900, and a through hole H.

As shown in FIG. 1A, the rigid flex circuit board 10″ also includes aflexible circuit board 100′, a first adhesive layer 200″, a first rigidcircuit board 300″, a second adhesive layer 600″, and a second rigidcircuit board 700″. The flexible circuit board 100′ includes a bendingportion B and a jointing portion A connected to the bending portion B.The first rigid circuit board 300″ and the second rigid circuit board700″ are disposed on two sides of the flexible circuit board 100′.Specifically, the first rigid circuit board 300″ and the second rigidcircuit board 700″ are disposed on two sides of the jointing portion Aof the flexible circuit board 100′, which exposes the bending portion B.The first adhesive layer 200″ is connected to the first rigid circuitboard 300″ and one of the sides of the jointing portion A, and thesecond adhesive layer 600″ is connected to the second rigid circuitboard 700″ and the other side of the jointing portion A.

Moreover, in the instant embodiment, the quantity of the jointingportion A is two and the quantity of the bending portion B is one, inwhich the one bending portion B is arranged between the two jointingportions A. However, the configuration of the bending and jointingportions A, B is not limited hereto. In another embodiment, one jointingportion A is connected to one bending portion B. In addition, therespective quantity of both the jointing portion A and bending portion Bcan be more than one, and one bending portion B is arranged between twojointing portion.

Furthermore, in the instant embodiment, the rigid flex circuit board 10″includes the flexible circuit board 100′, the first rigid circuit board300″, and the second rigid circuit board 700″, where the flexiblecircuit board 100′ is arranged between the first rigid circuit board300″ and the second rigid circuit board 700″. However, the quantities ofthe flexible circuit board and the rigid circuit board are not limitedin the instant disclosure. In another embodiment, the flexible circuitboard may only include one layer of flexible circuit board, and onelayer of rigid circuit board arranged on top of the jointing portion ofthe flexible circuit board.

Notably, the flexible circuit board 100″, the first rigid circuit board300″ and the second rigid circuit board 700″ include a plurality ofinsulating layers and circuit layers (one layer of insulating layer andone layer of circuit layer are shown in figures). The first adhesivelayer 200″ and the second adhesive layer 600″ can be made ofpolypropylene (PP) resin, but not limited hereto. The first adhesivelayer 200″ and the second adhesive layer 600″ can also be made of otherpolymer adhesives.

In FIG. 1A, the high-density interconnected circuit board 800 isdisposed in the rigid flex circuit board 10″ and is electricallyconnected to the first rigid circuit board 300″, the flexible circuitboard 100′ and the second rigid circuit board 700″. Specifically, therigid flex module 1 has a second opening h2. The second opening h2 isformed through the first rigid circuit board 300″, the flexible circuitboard 100′ and the second rigid circuit board 700″. Moreover, the secondopening h2 may have a cross-sectional shape of a non-point symmetricpattern, such as the shape of a lightning bolt, whereas the high-densityinterconnected circuit board 800 has a cross-sectional shape identicalto that of the second opening h2. Since the cross-sectional shape of thesecond opening h2 is a non-point symmetric pattern, the high-densityinterconnected circuit board 800 can be properly disposed in the secondopening h2, which facilitates the conductive posts 900 formingdownstream can be properly and electrically connected to the pads (notlabeled in figures) on the high-density interconnected circuit board800.

Notably, the high-density interconnected circuit board 800 is formed bya plurality of insulating layers and circuit layers. In terms ofthickness of the high-density interconnected circuit board 800, thetotal number of circuit layer is larger than the total number of therigid flex circuit board 10″, or larger than the total number of thefirst rigid circuit board 300″, the flexible circuit board 100′, and thesecond rigid circuit board 700″ combined. In other words, the density ofthe circuit layer of the high-density interconnected circuit board 800is larger than the circuit layer density of the rigid flex circuit board10″. In addition, the high-density interconnected circuit board 800 inthe instant embodiment amounts to one as shown in FIG. 1A. However, inanother embodiment, the quantity of the high-density interconnectedcircuit board 800 is more than one, and not limited hereto.

Moreover, the high-density interconnected circuit board 800 is disposedin the rigid flex circuit board 10″ in the instant embodiment. Inpractice, the high-density interconnected circuit board 800 and therigid flex circuit board 10″ can be separately designed. The design ofthe rigid flex circuit board 10″ can be relatively simple, in which thesecond opening h2 is formed in the rigid flex circuit board 10″ at aregion where dense circuitry may be required, then separately design thehigh-density interconnected circuit board 800, and dispose thehigh-density interconnected circuit board 800 into the second openingh2. The rigid flex board module 1 of the instant disclosure can firstselect the high-density interconnected circuit board 800, which reducespoor installation of the high-density interconnected circuit board 800and increases yield, whereas the conventional arts, the high-densityinterconnected circuit board 800 is directly design on the module toprovide dense circuitry.

Furthermore in FIG. 1A, the rigid flex board module 1 further includestwo pairs of multi-layer circuit layers 410′, 420′, the conductive posts900 and the through hole H. The multi-layer circuit layers 410′ aredisposed on two sides of both the rigid flex circuit board 10′ and thehigh-density interconnected circuit board 800. In other words, the firstrigid circuit board 300″, the flexible circuit board 100′, the secondrigid circuit board 700″, and the high-density interconnected circuitboard 800 are arranged between the pair of multi-layer circuit layers410′. Specifically, one of the multi-layer circuit layers 410′ isattached to one side of the first rigid circuit board 300″ and one sideof the high-density interconnected circuit board 800, whereas the othermulti-layer circuit layer 410′ is attached to one side of the secondrigid circuit board 700″, and the other side of the high-densityinterconnected circuit board 800. Moreover, the multi-layer circuitlayers 410′ expose the bending portion B.

Notably, the multi-layer circuit layers 410′ includes at least oneadhesive layer and at least one circuit layer (not shown in figures).The adhesive layer is made of polypropylene or other polymer adhesives,but not limited hereto. The multi-layer circuit layers 420′ arerespectively disposed on the multi-layer circuit layers 410′ exposingthe bending portion B. The conductive posts 900 provide electricalconnectivity between the multi-layer circuit layers 410′, themulti-layer circuit layers 420′, the high-density interconnected circuitboard 800, the first rigid circuit board 300″, and the second rigidcircuit board 700″. The through hole H passes through the rigid flexcircuit board 10″ in order to interconnect internal circuits of therigid flex circuit board 10″.

Aforementioned is the structure of the rigid flex board module 1 of theinstant embodiment. The instant disclosure also includes a manufacturingmethod for the rigid flex board module 1. Please refer to FIG. 1B to 1G.As shown in FIG. 1B, the first step includes providing a rigid flexinitial substrate 10. The rigid flex initial substrate 10 includes aflexible circuit board 100, a pair of release layers 500, a firstinsulating layer 200, a first rigid substrate 300, a second insulatinglayer 600, and a second rigid substrate 700. The flexible circuit board100 includes a bending portion B, and a jointing portion A connected tothe bending portion B. The release layers 500 are respectively disposedon two sides of the flexible circuit board 100 covering the bendingportion B. The first rigid substrate 300 and the second rigid substrate700 are respectively disposed on two release layer 500s and the flexiblecircuit board 100 covers the jointing portion A and the bending portionB of the flexible circuit board 100. The first insulating layer 200 isconnected between the first rigid substrate 300 and the flexible circuitboard 100, whereas the second insulating layer 600 is connected betweenthe second rigid substrate 700 and the flexible circuit board 100.

Notably, the flexible circuit board 100, the first rigid substrate 300and the second rigid substrate 700 include a plurality of insulatinglayers and circuit layers (figure shows only one insulating layer andone circuit layer).

In addition, one bending portion B is arranged between two jointingportions in the instant embodiment, but not limited hereto. In anotherembodiment, only one jointing portion A is connected to one bendingportion B. Besides, the quantities of the jointing portion A and thebending portion B can be more than one, as long as one bending portion Bis arranged between two jointing portions A.

Moreover, the rigid flex initial circuit board 10 includes the firstrigid substrate 300, the second rigid substrate 700, and the flexiblecircuit board 100 arranged between the first and second rigid substrate300, 700 in the instant embodiment. However, the quantities of theflexible circuit board 100 and the rigid circuit boards are not limitedto examples provided herein. In another embodiment, the rigid flexinitial circuit board 10 can only include a layer of rigid substrate anda layer of flexible circuit board.

Please refer to FIG. 1C. A pair of first openings h1 is formed in therigid flex initial substrate 10′ corresponding to the position of thebending portion B. As shown in FIG. 1C, one of the first openings h1 isformed through the first rigid substrate 300′ and the first insulatinglayer 200′ to expose one of the sides of one release layer 500 on theflexible circuit board 100. The other first opening h1 is formed throughthe second rigid substrate 700′ and the second insulating layer 600′ toexpose one of the sides of another release layer 500. In other words,the first openings h1 expose two sides of the bending portion B offlexible circuit board 100 while the pair of release layers 500 canprotect the flexible circuit board where the bending portion B islocated.

Notably, portions of each of the following the first rigid substrate300″, the first insulating layer 200″, the second insulating layer 600″,the second rigid substrate 700″ are removed by ultraviolet laser,routing or punching. In addition, the release layers 500 on two sides ofthe bending portion B can be protective layers of the flexible circuitboard 100′ to prevent damages therefrom during removal.

Please refer to FIG. 1D. One second opening h2 is formed in the rigidflex circuit board 10″ corresponding to the position of the jointingportion A. As shown in FIG. 1D, the second opening h2 passes through thefirst rigid substrate 300″, the first insulating layer 200″, theflexible circuit board 100″, the second insulating layer 600″, and thesecond rigid substrate 700″. Notably, the second opening h2 may have across-sectional shape of a non-point symmetric pattern such as alightning bolt. Moreover, the second opening h2 can be formed byultraviolet laser (UV), routing, or punching. Thereafter, forming athrough hole H in the rigid flex circuit board 10″. The through hole Hpasses through the first rigid substrate 300″, the first insulatinglayer 200″, the flexible circuit board 100′, the second insulating layer600″, and the second rigid substrate 700″. The through hole H is forelectrically jointing the internal circuits of the rigid flex circuitboard 10″.

Please refer to FIG. 1E. The rigid flex circuit board 10″ is disposed ona carrier 20. The carrier 20 has a plurality of fixing members 22 to fixthe rigid flex circuit board 10″. The fixing members 22 extend onto thefirst rigid circuit board 300″. The carrier 20 also has a buffermaterial 30 and a multi-layer circuit layer 410 arranged thereon. Thesecond rigid substrate 700″ of the rigid flex circuit board 10″ isattached on the multi-layer circuit layer 410.

Notably, the multi-layer circuit layer 410 includes at least oneadhesive layer and at least one circuit layer (not labeled in figures),and the multi-layer circuit layer 410 has a first opening h1 parallel tothe second opening h2. The adhesive layer can be made of polypropyleneresin or other polymer adhesives, but not limited hereto. Furthermore,the buffer layer 30 can be made of polyethylene terephthalate (PET), butnot limited hereto. The buffer layer 30 is arranged between themulti-layer circuit layer 410 and the carrier 20 to prevent attachmenttherebetween.

Thereafter, the high-density interconnected circuit board 800 isdisposed in the second opening h2. Notably, the high-densityinterconnected circuit board 800 has a cross-sectional shape of anon-point symmetric patter, which is identical to the cross-sectionalshape of the second opening h2, such that the high-densityinterconnected circuit board 800 can be fittingly align with anddisposed in the second opening h2.

Furthermore, the high-density interconnected circuit board 800 is alsoformed by a plurality of adhesive layers, insulating layers, and circuitlayers. The total number of circuit layers of the high-densityinterconnected circuit board 800 is larger than the total number ofcircuit layers of the rigid flex circuit board 10″. The total number ofcircuit layers of the rigid flex circuit board 10″ includes the totalnumber of layers of the first rigid substrate 300″, the flexible circuitboard 100′, and the second rigid substrate 700″. In addition, as shownin FIG. 1E, one high-density interconnected circuit board 800 is in theinstant embodiment, but the quantity is not limited hereto. In anotherembodiment, the high-density interconnected circuit board 800 can bemore than one.

Notably, one high-density interconnected circuit board 800 is disposedin the rigid flex circuit board 10″ in the instant embodiment. Inpractice, the high-density interconnected circuit board 800 and therigid flex circuit board 10″ can be separately designed. The design ofthe rigid flex circuit board 10″ can be relatively simple and lesslayers. The second opening h2 is formed in the rigid flex circuit board10″ at a region where dense circuitry may be required, then separatelydesign the high-density interconnected circuit board 800, and disposethe high-density interconnected circuit board 800 into the secondopening h2. The rigid flex board module 1 of the instant disclosure canfirst select the high-density interconnected circuit board 800, whichreduces poor installation of the high-density interconnected circuitboard 800 and increases yield, whereas the conventional arts, thehigh-density interconnected circuit board 800 is directly design on themodule to provide dense circuitry.

The other multi-layer circuit layer 410 covers on the first rigidsubstrate 300″ and the high-density interconnected circuit board 800such that the rigid flex circuit board 10″ and the high-densityinterconnected circuit board 800 are arranged between the pair ofmulti-layer circuit layers 410. Then, the buffer layer 30 is disposed onthe upper multi-layer circuit layer 410. The buffer layer 30 is toprotect the multi-layer circuit layer 410. Notably, the fixing member 22of the carrier 20 extends onto the upper multi-layer circuit layer 410and the buffer layer 30, which fixes the multi-layer circuit layer 410and the buffer layer 30 to the rigid flex circuit board 10″, tofacilitate subsequent attachment steps.

Moreover, heat is added to the adhesive layer of the multi-layer circuitlayers 410 such that the adhesives fill up the first openings h1, whichprovides adhesion between the rigid flex circuit board 10″ and thehigh-density interconnected circuit board 800. After heating, theadhesive layer resembles a semi-liquid form and has adhesive properties,which temporarily fixes the rigid flex circuit board 10″ and thehigh-density interconnected circuit board 800 between the multi-layercircuit layers 410.

Please refer to FIG. 1F. The carrier 20 and the buffer layer 30 areremoved, and a pair of multi-layer circuit layers 420 is formed on themulti-layer circuit layers 410. The multi-layer circuit layer 420 alsoincludes at least one adhesive layer and a circuit layer (not labeled infigures, the adhesive layer is made of the same materials as themulti-layer circuit layer 410). The step where the multi-layer circuitlayer 420 is formed on the multi-layer circuit layer 410 furtherincludes the multi-layer circuit layer 420 attached on the multi-layercircuit layer 410. Thereafter, heat is added and pressed in order to fixthe multi-layer circuit layers 420 on two sides of the high-densityinterconnected circuit board 800 and the rigid flex circuit board 10″.

After heat is added and pressed, the adhesive layer solidifies due tophase transition and cannot return to the original state. Notably, whenthe adhesive layer is heated, portions of the adhesive layer flow to agap between the high-density interconnected circuit board 800 and thesecond opening h2, such that the high-density interconnected circuitboard 800 is fixed in the rigid flex circuit board 10″.

Please refer to FIG. 1G. A plurality of conductive posts 900 is formed.Conductive posts 900 can provide electrical connections between themulti-layer circuit layer 420, multi-layer circuit layer 410, rigid flexcircuit board 10″, and the high-density interconnected circuit board800.

Please refer again to FIG. 1A. The release layer 500 is removed toexpose the bending portion B on two sides of the flexible circuit board100′, thus forming the rigid flex board module 1. Since the bendingportion B of the flexible circuit board 100′ is exposed, the rigid flexboard module 1 can be bent to provide rigid yet flexible properties.

In summary, the first embodiment of the instant disclosure firstly formthe first opening h1, the second opening h2, then multi-layering areperformed to form the multi-layer circuit layers 410, 420 on two sidesof the rigid flex circuit board 10″, thus forming the rigid flex boardmodule 1.

Please refer to FIG. 2A as the continuation from FIG. 1B which providesthe steps after the rigid flex initial substrate 10. Notably, thestructure of the rigid flex initial substrate 10 in FIG. 2A is similarto the structure in previous embodiment.

In the instant embodiment, after one rigid flex initial substrate 10 isprovided, one second opening h2 and one through hole H are formed in therigid flex circuit board 10″. The second opening h2 is correspondinglyformed at the position of the jointing portion A. The second opening h2is formed through the first rigid substrate 300″, the first insulatinglayer 200″, the flexible circuit board 100″, the second insulating layer600″, and the second rigid substrate 700″. The cross-sectional shape andthe formation of the second opening h2 and the through hole H aresimilar to the previous embodiment.

Please refer to FIG. 2B. The rigid flex circuit board 10″ is disposed onone carrier 20. The carrier 20 has a plurality of fixing members 22 tofix the rigid flex circuit board 10″. The carrier 20 has a buffer layer30 and a multi-layer circuit layer 410 thereon. The rigid flex circuitboard 10″ is arranged above the carrier 20, and the second rigidsubstrate 700″ of the rigid flex circuit board 10″ is attached on themulti-layer circuit layer 410.

The high-density interconnected circuit board 800 is then disposed inthe second opening h2. Notably, the high-density interconnected circuitboard 800 has a cross-sectional shape same as the second opening h2,such that the high-density interconnected circuit board 800 can alignwith and fittingly disposed in the second opening h2. As shown in FIG.2B, another multi-layer circuit layer 410 and buffer layer 30 cover overthe first rigid substrate 300″ and the high-density interconnectedcircuit board 800. Heat is then added such that the rigid flex circuitboard 10″ and the high-density interconnected circuit board 800 arefixed between the multi-layer circuit layers 410.

Please refer to FIG. 1A. One pair of multi-layer circuit layer 420 isformed on the multi-layer circuit layer 410. After heat is added andpressed, the multi-layer circuit layer 420 is fixed at two sides of therigid flex circuit board 10″, the high-density interconnected circuitboard 800, and the multi-layer circuit layer 410. Moreover, a pluralityof conductive posts 900 are formed such that the multi-layer circuitlayers 420, the multi-layer circuit layers 410, the rigid flex circuitboard 10″, and the high-density interconnected circuit board 800 areelectrically connected to each other.

Successively, a pair of first openings h1 is formed in the rigid flexinitial substrate 10′ corresponding to the position of the bendingportion B. The pair of first openings h1 exposes the bending portion Bon two sides of the flexible circuit board 100, thus forming the rigidflex board module 1. The first openings h1 can be formed by ultraviolet(UV) laser, routing, or punching. In addition, since the flexiblecircuit board 100′ exposes the bending portion B, the rigid flex boardmodule 1 can be bent to provide flexible yet rigid properties.

In summary, in the second embodiment of the instant disclosure, thesecond openings h2 are first formed, and the multi-layer circuit layers410, 420 are formed on two sides of the rigid flex circuit board 10″.Successively, the pair of first openings h1 is formed to expose thebending portion B on two sides of the flexible circuit board 100. Thus,the rigid flex board module 1 is formed.

Notably in the first embodiment of the instant disclosure, themulti-layer circuit layer 410 having the first opening h1 is pressedafter the first opening h1 is formed, which is more preferred for rigidflex board module 1 having a relatively thick first rigid substrate300″, in order to reduce the poor accuracy in forming the openings orpoor yield due to the relatively thick substrate. In the secondembodiment, the procedure differs in that the first opening h1 is formedspecifically at the position of the first opening h1 in the last step,which is more preferred for the rigid flex board module 1 having arelatively thin first rigid substrate 300″.

Moreover, the first and the second embodiments of the instant disclosurediffer in the sequence of forming the first opening h1, second openingh2, and the multi-layering. Other structures such as the high-densityinterconnected circuit board 800 are substantially the same as previousembodiment, thus not further discussed.

Please refer to FIG. 3. The structure of the rigid flex board module 1′is substantially the same as the previous embodiment, which alsoincludes the rigid flex circuit board 10″, the high-densityinterconnected circuit board 800, two pairs of multi-layer circuit layer410′, 420′, and the plurality of conductive posts 900. The rigid flexcircuit board 10″ further includes the flexible circuit board 100′, thefirst adhesive layer 200″, the first rigid circuit board 300″, thesecond adhesive layer 600″, and the second rigid circuit board 700″.

However, the rigid flex board module 1′ of the instant embodimentdiffers from the rigid flex board module 1 of the first embodiment inthat the rigid flex board module 1′ has a first second opening h2′ whichpasses through the first rigid circuit board 300″ and the first adhesivelayer 200″. The high-density interconnected circuit board 800′ canfittingly align with and be disposed in the second opening h2′. Notably,the total number of circuit layer of the high-density interconnectedcircuit board 800′ is larger than the total number of circuit layer ofthe first rigid circuit board 300″ and the first adhesive layer 200″combined. In other words, the density of circuits in the circuit layerof the high-density interconnected circuit board 800′ is higher than thedensity of circuits in the first rigid circuit board 300″ and the firstadhesive layer 200″ combined.

Furthermore, in another embodiment, the second opening h2′ can alsopasses through the second adhesive layer 600″, and the second rigidcircuit board 700″. The total number of circuit layer of thehigh-density interconnected circuit board 800′ is larger than the totalnumber of circuit layer of the second adhesive layer 600″ and the secondrigid circuit board 700″ combined. The position of the high-densityinterconnected circuit board 800′ is not limited hereto.

In summary, the instant disclosure provides a rigid flex board module amanufacturing method of the same. The rigid flex board module includes arigid flex circuit board and a high-density interconnected circuitboard. The high-density interconnected circuit board is disposed in therigid flex circuit board in regions thereof where high density circuitryis preferred. Since the high-density interconnected circuit board andthe rigid flex circuit board can be separately designed, yield rate ofthe rigid flex circuit board can be successively increased.

The figures and descriptions supra set forth illustrated the preferredembodiments of the instant disclosure; however, the characteristics ofthe instant disclosure are by no means restricted thereto. All changes,alternations, combinations or modifications conveniently considered bythose skilled in the art are deemed to be encompassed within the scopeof the instant disclosure delineated by the following claims.

What is claimed is:
 1. A manufacturing method for a rigid flex boardmodule, comprising: providing a rigid flex initial substrate including aflexible circuit board, a pair of release layers, a first rigidsubstrate, and a first insulating layer; wherein the flexible circuitboard having a bending portion and a jointing portion connected to thebending portion, the pair of release layers respectively disposed on twosides of the flexible circuit board covering the bending portion, thefirst rigid substrate arranged above the flexible circuit board and thepair of release layers, the first rigid substrate covering the bendingportion and the jointing portion, and the first insulating layerconnected between the first rigid substrate and the flexible circuitboard; forming a pair of first openings on the rigid flex initialsubstrate to expose the bending portion; forming a second openingthrough the rigid flex initial substrate, the first rigid substrate andthe first insulating layer; disposing a high-density interconnectedcircuit layer in the second opening; forming a pair of multi-layercircuit layers on two sides of the rigid flex initial substrate andcovering two sides of the high-density interconnected circuit layer andthe rigid flex initial substrate; and forming a plurality of conductiveposts such that the multi-layer circuit layers, the high-densityinterconnected circuit layer, and the rigid flex initial substrate areelectrically connected to each other.
 2. The manufacturing method forthe rigid flex board module as recited in claim 1, wherein the rigidflex initial substrate further comprising: a second rigid substratedisposed on the flexible circuit board, and the flexible circuit boardarranged between the first rigid substrate and the second rigidsubstrate; and a second insulating layer connected between the secondrigid substrate and the jointing portion.
 3. The manufacturing methodfor the rigid flex board module as recited in claim 1, wherein thesecond opening is formed through the first rigid substrate, the firstinsulating layer, the flexible circuit board, the second insulatinglayer and the second rigid substrate.